Mechanics

P0300 MISFIRE

2003 Mitsubishi Montero

Engine Mechanical problem
2003 Mitsubishi Montero 6 cyl All Wheel Drive Automatic 121000 miles

Montero Sport
Got this code a month ago and was told that the valve cover gasket was leaking and oil was getting down into the spark plugs. Had them replace plugs, wires, and gasket. Couple of days later the same code came up again. They put on their machine and drove it. Found the mass air flow was running at 60-70 and would drop to 40 (cfm I'm guessing). They changed that out but still did the same thing. They don't know what else to do so they told me to take it to the dealer. If anyone has come across this I would appreciate knowing.
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Gregoppold
January 17, 2010.




2003 Mitsubishi Montero P0300 misfire

Normally points to false air/vacuum leaks and contaminated fuel

Engine misfiring can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

Tiny
Rasmataz
Jan 17, 2010.


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